FAQ: Regular Expression Features

Short Answer

You can use whatever's documented (Regular Expressions), and possibly more. How much more you can use depends on your platform.

Long Answer

Regular expressions are not fully standardized -- different programs that support
"regular expression" may support slightly different features. For instance,
some will let you use {N} to repeat the preceding expression N times, and some will not
(they will require you to write the expression N times yourself).
Some will let you use \d to match any digit, and others will not (they will require you to
use [0-9]. So the point of this question is, which of these "non-standard" features
does Sawmill support? The answer depends on the platform you're running Sawmill on.

Sawmill's regular expressions vary depending on platform -- it uses the built-in
regular expression library on some platforms,
and the Boost library on others. Anything that is documented in Regular Expressions is available
on all platforms. Anything that is not documented there may not be available.
The easiest way to find out if something is available is to try it -- add a
regular-expression filter to your Log Filters and see if it works.
But if you want to make sure your profile is portable, and will work on other
platforms, you should stick to the documented choices.